I don't, actually. From what I've gathered from the reference pics, each stripe
is basically a plain rectangle. There's no noticeable taper from bottom to top.
Here's one of the most oblique shots I have from one of the AoSW exhibits.
I've taken a chunk from the bottom of the stripe and moved it to the top of
the stripe. There doesn't appear to be any reduction in width.
[ATTACH=full]133019[/ATTACH]
I think that since the stripes are so close to the base of the dome, and that they are
not that tall relative to the overall height of the dome, masking them as rectangles works
well. If the stripes were, say, twice as tall, then they would have to have some sort of
taper if the goal was to keep the space between them even.